Vastus Lateralis and Vastus Intermedius as Predictors of Quadriceps Femoris Muscle Hypertrophy after Strength Training

Round 1

Reviewer 1 Report

The Reviewer thanks the Authors for this interesting paper looking at the assessment of the components of the quadriceps muscle. The clinical utility of using ultrasound to identify training-induced changes in the muscle to assess as a proxy for quadriceps function following resistance training is potentially useful evidence for monitoring rehabilitation following injury.
A few comments

1.    Paragraph 1, line 1: Quadriceps femoris consists by four …… This sentence could be amended to Quadriceps femoris consists of four……….

2.    Page 5, could the text for the description of Table 1 come before the Table?

3.    Typos:

-      page 2, line 82 check spelling of through

-      page 4, line 48 repetition

4.    Discussion: Page 7 lines 212-216: “The main finding of the present study was that the ultrasonographic evaluation of VL and VI CSA training-induced changes, could efficiently represent, predictand and explain the whole quadriceps muscle hypertrophy after strength training, at least when muscle hypertrophy is evaluated at the point of 40% proximal to the kne”- this sentence is unclear and needs to be re-written

5.    Page 7, lines 216-218 is a repetition of previous statement. Should be deleted. “Therefore, it seems that both VL and VI CSAs’ training-induced changes are good surrogates of the whole quadriceps training-induced hypertrophy, when it is evaluated through ultrasonography”.

6.    Page 7 lines 233-237:  “Furthermore, these results provide strong evidence indicating 233 that VL apart from being more accessible than the other muscle heads and ultrasound imaging is easier and more achievable, the evaluation of its CSA training-induced changes, may also replace the need for the evaluation of the whole quadriceps muscle hypertrophy”; the rationale for the study is sufficient, but the study has a rather small sample size and as such the authors need to include a note of caution in interpreting the results. A statement as above in the discussion rather comes across more as if this was a larger powered study. It will be useful if the authors review the discussion section, conclusion, and abstract sections in particular and temper the interpretations and conclusions accordingly given the sample size of an under-powered study.

Author Response

Reviewers’ Comment

 

Reviewer 1

 

Comment to the Authors

The Reviewer thanks the Authors for this interesting paper looking at the assessment of the components of the quadriceps muscle. The clinical utility of using ultrasound to identify training-induced changes in the muscle to assess as a proxy for quadriceps function following resistance training is potentially useful evidence for monitoring rehabilitation following injury.

 

Authors’ Response

We would like to thank the reviewer for the time spent on this manuscript, his/her warm word about our manuscript and the valuable comments and suggestions. We have now revised our manuscript according to reviewer’s suggestions. Below you can find our point by point responses.

 

Comment to the Authors

1. Paragraph 1, line 1: Quadriceps femoris consists by four …… This sentence could be amended to Quadriceps femoris consists of four……….

 

Authors’ Response

We have now changed this part of the manuscript accordingly (Line 35)

 

Comment to the Authors

2. Page 5, could the text for the description of Table 1 come before the Table?

Authors’ Response

We have now changed this part of the manuscript accordingly (Lines 186-197)

 

Comment to the Authors

 page 2, line 82 check spelling of through

 

Authors’ Response

We have now changed this part of the manuscript accordingly (Line 84)

 

Comment to the Authors

 page 4, line 48 repetition

 

Authors’ Response

We have now changed this part of the manuscript accordingly

 

 

 

 

 

 

 

Comment to the Authors

3. Discussion: Page 7 lines 212-216: “The main finding of the present study was that the ultrasonographic evaluation of VL and VI CSA training-induced changes, could efficiently represent, predictand and explain the whole quadriceps muscle hypertrophy after strength training, at least when muscle hypertrophy is evaluated at the point of 40% proximal to the kne”- this sentence is unclear and needs to be re-written

 

Authors’ Response

We have now re-phrase this part of the manuscript according to reviewer suggestion (Lines 220-224)

 

“The main finding of the present study was that training-induced changes of VL and VI CSAs, may be good surrogates of the whole quadriceps muscle hypertrophy following strength training, at least when the CSAs are evaluated with ultrasonography and at the 40% of the distance between the center of the patella and medial aspect of the anterior superior iliac spine, proximal to knee.”

 

Comment to the Authors

4. Page 7, lines 216-218 is a repetition of previous statement. Should be deleted. “Therefore, it seems that both VL and VI CSAs’ training-induced changes are good surrogates of the whole quadriceps training-induced hypertrophy, when it is evaluated through ultrasonography”.

 

Authors’ Response

Thank you for pointing this out. We have now deleted this part of the manuscript, in our revised manuscript.

 

Comment to the Authors

5. Page 7 lines 233-237:  “Furthermore, these results provide strong evidence indicating 233 that VL apart from being more accessible than the other muscle heads and ultrasound imaging is easier and more achievable, the evaluation of its CSA training-induced changes, may also replace the need for the evaluation of the whole quadriceps muscle hypertrophy”; the rationale for the study is sufficient, but the study has a rather small sample size and as such the authors need to include a note of caution in interpreting the results. A statement as above in the discussion rather comes across more as if this was a larger powered study. It will be useful if the authors review the discussion section, conclusion, and abstract sections in particular and temper the interpretations and conclusions accordingly given the sample size of an under-powered study.

Authors’ Response

Thank you for pointing this out. We have now deleted this part of the manuscript, in our revised manuscript. We have now changed several parts of the revised manuscript according to reviewer’s suggestions.

 

Again we would like to thanks the reviewer for his/her warm review on our manuscript and comments

Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for the opportunity to review this interesting study which aimed to identify using ultrasonography, which of the four quadriceps muscle heads I the most appropriate surrogate of a hypertrophic response. The authors have presented interesting data which suggests that the VL and VI may be the most valid surrogates in both clinical and sport science research. The results are presented clearly and discussed appropriately in the context of their contribution to the literature. One issue, or rather disappointment is the fact no females participants were recruited. Was this due to failure in the recruitment strategy? No details are given other than no females were recruited. The paper on the whole is written clearly and the methodology is sound. I have only only minor changes to recommend (please see below). 

Abstract

line 14 - i believe 'the' should be added before quadriceps

line 28 - 'be' to be added after may

introduction

line49 - remove 'but mostly'

line 68 - remove 'a' after provide

methods 

line 118 - was encouragement standardised across all participants? Add something here detailing if so

line 125 - change enter to entered

Was the ultrasonography carried out by the same researcher? Add details in this section about the standardisation of the technique

discussion

line 214 - remove one and after predict

 

 

Author Response

Reviewers’ Comment

 

Reviewer 2

 

Comment to the Authors

Thank you for the opportunity to review this interesting study which aimed to identify using ultrasonography, which of the four quadriceps muscle heads I the most appropriate surrogate of a hypertrophic response. The authors have presented interesting data which suggests that the VL and VI may be the most valid surrogates in both clinical and sport science research. The results are presented clearly and discussed appropriately in the context of their contribution to the literature. One issue, or rather disappointment is the fact no females participants were recruited. Was this due to failure in the recruitment strategy? No details are given other than no females were recruited. The paper on the whole is written clearly and the methodology is sound. I have only only minor changes to recommend (please see below). 

 

Authors’ Response:

We would like to thank the reviewer for the time spent on this manuscript, his/her warm word about our manuscript and the valuable comments and suggestions. We have now revised our manuscript according to reviewer’s suggestions. Below you can find our point by point responses.

As for the comment about the absence of female participants, the present study was the first investigating this issue, thus we choose to include only male participants to avoid influences that may affect the size and composition of muscle mass, adipose tissue and fluid retention, which may negatively affect the objective assessment of muscle mass, such as the menstrual cycle. We hope that in a future study we will investigate this also in female participants.

 

 

Comment to the Authors

line 14 - i believe 'the' should be added before quadriceps

 

Authors’ Response:

We have now changed this part of the manuscript accordingly

 

Comment to the Authors

line 28 - 'be' to be added after may

 

Authors’ Response:

We have now changed this part of the manuscript accordingly

 

Comment to the Authors

line49 - remove 'but mostly'

 

Authors’ Response:

We have now changed this part of the manuscript accordingly

 

Comment to the Authors

line 68 - remove 'a' after provide

 

Authors’ Response:

We have now changed this part of the manuscript accordingly

 

Comment to the Authors

line 118 - was encouragement standardised across all participants? Add something here detailing if so

 

Authors’ Response:

Yes the encouragement was standardized across all participants, by saying loudly “lift, lift, lift….”, We have now added this information in the revised manuscript (Lines 121-122)

“…..by a standardized procedure”

 

 

Comment to the Authors

line 125 - change enter to entered

 

Authors’ Response:

We have now changed this part of the manuscript accordingly

 

Comment to the Authors

Was the ultrasonography carried out by the same researcher? Add details in this section about the standardisation of the technique

 

Authors’ Response:

Thank you for this comment. Indeed, the same investigator performed all the evaluations. We have now added this information in our revised manuscript, according to reviewer’s suggestion (Line 127):

“….always by the same investigator – co-author.”

 

Comment to the Authors

line 214 - remove one and after predict

 

Authors’ Response:

This part of the manuscript has been re-phrased according to the other reviewer’s comment

Again we would like to thanks the reviewer for his/her warm review on our manuscript and comments

Author Response File: Author Response.pdf